Small-angle light scattering symmetry breaking in polymer-dispersed liquid crystal films with inhomogeneous electrically controlled interface anchoring

• Published in: Journal of experimental and theoretical physics Vol. 124; no. 3; pp. 388 - 405
• Main Authors: Loiko, V. A., Konkolovich, A. V., Zyryanov, V. Ya, Miskevich, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-03-2017; Springer; Springer Nature B.V
• Subjects: Analysis; ANGULAR DISTRIBUTION; Approximation; APPROXIMATIONS; ASYMMETRY; Atoms; Broken symmetry; Classical and Quantum Gravitation; CONCENTRATION RATIO; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Crystal structure; DIFFRACTION; Disk drives; DROPLETS; Electro-optical effect; Elementary Particles; Energy distribution; FREE ENERGY; Hard disk drives; ILLUMINANCE; Illumination; Incident waves; INTERFACES; INTERFERENCE; LIGHT SCATTERING; LIQUID CRYSTALS; Luminous intensity; MAGNETIC DISKS; Molecular structure; MOLECULES; Optics; Orientation effects; Particle and Nuclear Physics; PHASE SHIFT; Physics; Physics and Astronomy; Polydispersity; Polymer films; POLYMERS; Quantum Field Theory; Relativity Theory; Skewed distributions; Solid State Physics; SURFACES; SYMMETRY BREAKING; Wave diffraction; Wave dispersion; Wave fronts; Wave scattering
• ISSN: 1063-7761; 1090-6509
• DOI: 10.1134/S1063776117020133

We have described the method of analyzing and reporting on the results of calculation of the small-angle structure of radiation scattered by a polymer-dispersed liquid crystal film with electrically controlled interfacial anchoring. The method is based on the interference approximation of the wave scattering theory and the hard disk model. Scattering from an individual liquid crystal droplet has been described using the anomalous diffraction approximation extended to the case of droplets with uniform and nonuniform interface anchoring at the droplet–polymer boundary. The director field structure in an individual droplet is determined from the solution of the problem of minimizing the volume density of the free energy. The electrooptical effect of symmetry breaking in the angular distribution of scattered radiation has been analyzed. This effect means that the intensities of radiation scattered within angles +θ
s
and–θ
s
relative to the direction of illumination in the scattering plane can be different. The effect is of the interference origin and is associated with asymmetry of the phase shift of the wavefront of an incident wave from individual parts of the droplet, which appears due to asymmetry of the director field structure in the droplet, caused by nonuniform anchoring of liquid crystal molecules with the polymer on its surface. This effect is analyzed in the case of normal illumination of the film depending on the interfacial anchoring at the liquid crystal–polymer interface, the orientation of the optical axes of droplets, their concentration, sizes, anisometry, and polydispersity.